It has long been known that the two hemispheres of the human brain control different functions of the body and the psychological state of a person. Fredric Schiffer, M.D. is a pioneer in dual-brain psychological studies. He started with two pairs of ordinary goggles and modified them by taping over the left side and part of the right side of one pair and by taping over the right side and part of the left side of the other pair. This was obviously a make-shift, do-it-yourself modification of the goggles. However, it allowed Dr. Schiffer to restrict the wearer's field of view to the outer periphery of one eye or the other by merely having him or her wear one or the other pairs of the goggles. Dr. Schiffer has found that by having the subject wear one pair of the modified goggles and then the other that it is possible to independently access each hemisphere of a subject's brain in order to get an indication of the mental state of a subject. He discovered that many people experienced an increase or decrease in their psychological symptoms as a function of accessing one lobe of the brain as opposed to the other.